Power control circuits are typically utilized to control the operation of power devices such as protecting power devices from large surge currents that could destroy the device.
One way of accomplishing this is to couple an silicon controlled rectifier (SCR) across the input capacitance of a power device. When the SCR is latched due to a predetermined condition occurring, the input capacitance of the power device is discharged, thereby decreasing the voltage across the input capacitance to a level determined by the forward on voltage of the SCR. However, once the voltage across the input capacitance decreases below the forward on voltage of the SCR, the SCR unlatches. The input capacitance is then free to be charged up again. Moreover, once the predetermined condition is satisfied again, the SCR will latch and the above process will be repeated and, thus, become oscillatory.
Hence, there is a need for an improved device for use in power control circuits that retains the memory that an SCR was latched.